 /*
  * Mango CMS
  * Copyright 2008, Mango Web, and individual contributors as indicated
  * by the @authors tag. See the copyright.txt in the distribution for a
  * full listing of individual contributors.
  *
  * This is free software; you can redistribute it and/or modify it
  * under the terms of the GNU Lesser General Public License as
  * published by the Free Software Foundation; either version 2.1 of
  * the License, or (at your option) any later version.
  *
  * This software is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with this software; if not, write to the Free
  * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
  */
package org.mangocms.utils.crypto;

import org.apache.commons.codec.binary.Base64;
import org.apache.commons.codec.digest.DigestUtils;

/**
 * A StringEncrypter.
 * 
 * @author <a href="tanordheim@gmail.com">Trond Arve Nordheim</a>
 * @version $Revision: 1.1 $
 */
public class StringEncrypter {
	
	/**
	 * Create a new StringEncrypter.
	 * This constructor is private, preventing class instantiation. All public
	 * methods on this class are available as static methods.
	 */
	private StringEncrypter() {
	}
	
	/**
	 * Encrypt a string using the specified cleartext string and salt, using
	 * the specified encryption method.
	 * 
	 * @param cleartext
	 * @param salt
	 * @param method
	 * @return
	 */
	public static String encryptAsBase64(String cleartext, String salt, EncryptionMethod method) {

		byte[] hash = getEncryptedHash(cleartext, salt, method);
		return new String(Base64.encodeBase64(hash));

	}
	
	/**
	 * Get the encrypted hash from the specified cleartext string and salt,
	 * using the specified encryption method.
	 * 
	 * @param cleartext
	 * @param salt
	 * @param method
	 * @return
	 */
	private static byte[] getEncryptedHash(String cleartext, String salt, EncryptionMethod method) {
		
		if (method.equals(EncryptionMethod.SHA1) == true)
			return DigestUtils.sha(cleartext + salt);
		
		if (method.equals(EncryptionMethod.MD5) == true)
			return DigestUtils.md5(cleartext + salt);

		throw new RuntimeException("Invalid encryption method specified: " + method);
		
	}

}
